|Wu, J - WASHINGTON STATE UNIV|
|Dun, S - WASHINGTON STATE UNIV|
|Elliot, W - USDA-FOREST SERVICE|
Submitted to: ASAE Annual International Meeting
Publication Type: Abstract Only
Publication Acceptance Date: July 17, 2005
Publication Date: July 17, 2005
Citation: Wu, J., Dun, S., Elliot, W., Flanagan, D.C. 2005. Assessing the newly incorporated subsurface water flow routines in the WEPP model [abstract]. ASAE Annual International Meeting. Tampa, FL, June 17-20, 2005. Technical Abstract: The USDA’s WEPP watershed model has demonstrated its usefulness in certain forest applications, e.g., erosion and sediment yield modeling for road segments or simple hillslopes. However, when used for simulating water flow and sediment discharge from a forest watershed of complex topography and channel systems, WEPP has been shown to consistently underestimate subsurface runoff and channel flow. The inadequate estimation of the hydrologic and hydraulic quantities often leads to erroneous estimation of erosion as well. Recently, the subsurface runoff routines in the WEPP model have been modified for better representation of the forest watershed conditions characterized by shallow soils overlying bedrock of relatively low permeability. Along with the modifications to the subsurface routines were changes to the WEPP soil input file. A group of input parameters have been added to the soil input file for user to describe and specify key hydraulic properties of the underlain bedrock. The main goal of this study is to thoroughly evaluate the newly incorporated subsurface routines in WEPP through the testing under a conceptual setting and validating against field data. Specifically, we will evaluate the modified routine using a conceptual forest watershed and determine the sensitivity of the model outputs to the newly included hydraulic property parameters. Additionally, we will evaluate the adequacy of the modified routines using multiple years of runoff data collected from Hermada Watershed, a small watershed located in the Boise National Forest in northern Idaho.